Flue gas modelling to meet WID

Key challenges

This grate furnace incineration plant firing bio-waste needed to ensure that the residence time of the flue gases was in excess of two seconds at 850° C in order to meet the Waste Incineration Directive that regulates emissions of dioxins and furans.

RJM Solution

RJM carefully modelled the behaviour of the post-combustion flue gases and created a series of restrictive baffles to slow their speed, thereby increasing the residence time.

Results

This was a new challenge for RJM, beyond its more conventional CFD work with PF fuels, but by gaining a thorough understanding of the issues, it developed a solution using CFD modelling and provided recommendations to the site to improve flue gas residence time to comply with the European Union’s Waste Incineration Directive (WID).